Surveys conducted over the Internet have become increasingly popular. In many online surveys, a user is offered a reward or an incentive, such as a coupon, an enrollment in a contest, and the like, in exchange for completing the online survey. Generally, the user completes the online survey without any supervision by the provider of the survey. Unfortunately, to more quickly obtain the incentive, many unsupervised users complete the online survey by providing inaccurate responses to the survey. In other scenarios, the user may not respond to the survey at all. Ultimately, the success and accuracy of the survey depends upon the user responses. In some examples, marketing strategies may be adjusted based on the user responses. However, if the user responses are inaccurate, the adjusted marking strategy may also be unreliable.